U.S. patent number 4,965,293 [Application Number 07/362,917] was granted by the patent office on 1990-10-23 for polyurea elastomers with improved surface quality.
This patent grant is currently assigned to Mobay Corporation. Invention is credited to Sanns, Jr. Frank.
United States Patent |
4,965,293 |
|
October 23, 1990 |
Polyurea elastomers with improved surface quality
Abstract
The present invention is directed to a process for the
production of optionally cellular, polyurea elastomer moldings by
reacting a mixture containing (I) a polyisocyanate component having
an isocyanate content of about 10 to 30% by weight which comprises
an isocyanate-terminated prepolymer prepared by reacting a
polyisocyanate with a non-fatty, hydroxy polyester having a
hydroxyl functionality of 1 to 4 and a molecular weight of about
500 to 4000, provided that if the hydroxy polyester is based on an
aliphatic monocarboxylic acid, the aliphatic monocarboxylic acid is
a non-fatty monocarboxylic acid containing less than 12 carbon
atoms, (II) a polyether having at least two isocyanate-reactive
groups and a molecular weight of 1800 to 12,000 in which at least
50% of the isocyanate-reactive groups are primary and/or secondary
amino groups, and (III) abotu 5 to 50% by weight, based on the
weight of component (II) of a chain extender comprising a
sterically hindered aromatic diamine, the reaction mixture being
processed as a one-shot system by the RIM process at an isocyanate
index of about 70 to 130. The present invention is also directed to
an isocyanate-reactive component for use in a RIM process based on
components, (II), (III), (IV) and (V) and to an internal mold
release agent mixture based on components (IV) and (V) and,
optionally, (III). finally, the present invention is directed to
the optionally cellular polyurea elastomers prepared by the above
process.
Inventors: |
Sanns, Jr. Frank (Pittsburgh,
PA) |
Assignee: |
Mobay Corporation (Pittsburgh,
PA)
|
Family
ID: |
23428046 |
Appl.
No.: |
07/362,917 |
Filed: |
June 8, 1989 |
Current U.S.
Class: |
521/124;
252/182.26; 264/328.1; 264/328.6; 264/328.8; 264/51; 524/783 |
Current CPC
Class: |
C08G
18/10 (20130101); C08G 18/4238 (20130101); C08G
18/5024 (20130101); C08K 5/098 (20130101); C08G
18/10 (20130101); C08G 18/6685 (20130101); C08G
18/10 (20130101); C08G 18/6696 (20130101); C08K
5/098 (20130101); C08L 75/02 (20130101); C08G
2101/00 (20130101); C08G 2120/00 (20130101) |
Current International
Class: |
C08K
5/098 (20060101); C08G 18/00 (20060101); C08K
5/00 (20060101); C08G 18/10 (20060101); C08G
18/50 (20060101); C08G 18/42 (20060101); C08G
018/14 () |
Field of
Search: |
;521/124 ;524/783
;252/182.26 ;264/51,328.1,328.6,328.8 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Welsh; Maurice J.
Attorney, Agent or Firm: Gil; Joseph C. Roy; Thomas W.
Claims
What is claimed is:
1. A process for the production of an optionally cellular, polyurea
elastomer molding which comprises reacting a reaction mixture
containing
(I) a polyisocyanate,
(II) a polyether having at least two isocyanate-reactive groups and
a molecular weight of 1800 to 12,000 in which at least 50% of the
isocyanate-reactive groups are primary and/or secondary amino
groups,
(III) about 5 to 50% by weight, based on the weight of component
(II), of a chain extender comprising a sterically hindered aromatic
diamine and
(IV) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of a zinc carboxylate containing 8 to 24 carbon
atoms per carboxylate group and
(V) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of an active hydrogen containing fatty acid ester
having a molecular weight of about 500 to 5000 and prepared by
reacting an alcohol with an aliphatic, saturated or unsaturated
fatty acid, said ester being characterized in that at least one
aliphatic acid which contains more than eight carbon atoms is built
into the molecule, said ester further characterized as having an
acid number of 0 to 100 and a hydroxyl number of 0 to 150 with at
least one cf said numbers being greater than 0,
wherein said zinc carboxylate and said fatty acid ester may each be
initially blended with either component (II), component (III) or a
mixture thereof and the reaction mixture is processed as a one-shot
system by the RIM process at an isocyanate index of about 70 to
130.
2. The process of claim 1 wherein about 80 to 100% of the
isocyanate-reactive groups of component (II) are primary and/or
secondary amino groups.
3. The process of claim 1 wherein said chain extender comprises an
isomeric mixture of 1-methyl-3,5-diethyl-2,4-diaminobenzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene.
4. The process of claim 1 wherein said fatty acid ester (V) has an
acid number of 0 to 40, a hydroxyl number of 0 to 75 and an average
molecular weight of about 800 to 3000.
5. The process of claim 1 wherein said alcohol used to prepare said
fatty acid ester (V) comprises a low molecular weight polyol having
3 or more hydroxyl groups.
6. The process of claim 1 wherein said fatty acid ester (V)
comprises the reaction product of a fatty acid, a dicarboxylic acid
and a low molecular weight polyol having 3 or more hydroxyl groups,
said fatty acid ester having an average molecular weight of about
900 to 2500, a hydroxyl number of about to 70 and an acid number of
about 3 to 30.
7. The process of claim 1 wherein said reaction mixture
additionally contains a reinforcing agent.
8. A process for the production of an optionally cellular, polyurea
elastomer molding which comprises reacting a reaction mixture
containing
(I) a polyisocyanate which is liquid at room temperature,
(II) a polyether having at least two isocyanate-reactive groups and
a molecular weight of about 2000 to 8000 in which about 80% to 100%
of the isocyanate-reactive groups are primary and/or secondary
amino groups,
(III) about 5 to 50% by weight, based on the weight of component
(II) of a chain extender comprising an isomeric mixture of
1-methyl-3,5-diethyl-2,4-diaminobenzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene,
(V) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of a zinc carboxylate containing 8 to 24 carbon
atoms per carboxylate group and
(IV) about 2 to 15% by weight, based on the weight of
components (II) and (III) of an active hydrogen-containing fatty
acid ester having a molecular weight of about 800 to 3000 and
prepared by reacting an alcohol with an aliphatic, saturated or
unsaturated fatty acid, said ester being characterized in that at
least one aliphatic acid which contains more than 8 carbon atoms is
built into the molecule, said ester further characterized as having
an acid number of 0 to 40 and a hydroxyl number of 0 to 75, with at
least one of said numbers being greater than 0,
wherein said zinc carboxylate and said fatty acid ester may each be
initially blended with component (II), component (III) or a mixture
thereof and the reaction mixture is processed as a one-shot system
by the RIM process at an isocyanate index of about 70 to 130.
9. The process of claim 8 wherein said alcohol used to prepare said
fatty acid ester (V) comprises a low molecular weight polyol having
3 or more hydroxyl groups.
10. The process of claim 8 wherein said fatty acid ester (V)
comprises the reaction product of a fatty acid, a dicarboxylic acid
and a low molecular weight polyol having 3 or more hydroxyl groups,
said fatty acid ester having an average molecular weight of about
900 to 2500, a hydroxyl number of about to 70 and an acid number of
about 3 to 30.
11. The process of claim 8 wherein said reaction mixture
additionally contains a reinforcing agent.
12. An isocyanate-reactive component which is suitable for the
production of an optionally cellular, polyurea elastomer molding
and comprises
(I) a polyether having at least two isocyanate-reactive groups and
a molecular weight of 1800 to 12,000 in which at least 50% of the
isocyanate-reactive groups are primary and/or secondary amino
groups,
(II) about 5 to 50% by weight, based on the weight of component
(ii), of a chain extender comprising a sterically hindered aromatic
diamine and
(IV) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of a zinc carboxylate containing 8 to 24 carbon
atoms per carboxylate group and
(V) about 1 to 20% by weight, based on the weight of components
(II) and (III), of an active hydrogen-containing fatty acid ester
having a molecular weight of about 500 to 5000 and prepared by
reacting an alcohol with an aliphatic, saturated or unsaturated
fatty acid, said ester being characterized in that at least one
aliphatic acid which contains more than 8 carbon atoms is built
into the molecule, said ester further characterized as having an
acid number of 0 to 100 and a hydroxyl number of 0 to 150 with at
least one of said numbers being greater than 0.
13. The isocyanate-reactive component of claim 12 wherein about 80
to 100% of the isocyanate-reactive groups of component (II) are
primary and/or secondary amino groups.
14. The isocyanate-reactive component of claim 12 wherein said
chain extender comprises an isomeric mixture of
1-methyl-3,5-diethyl-2,4-diamino-benzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene.
15. The isocyanate-reactive component of claim 12 wherein said
fatty acid ester (V) has an acid number of 0 to 40, a hydroxyl
number of 0 to 75 and an average molecular weight of about 800 to
3000.
16. The isocyanate-reactive component of claim 12 wherein said
alcohol used to prepare said fatty acid ester (V) comprises a low
molecular weight polyol having 3 or more hydroxyl groups.
17. The isocyanate-reactive component of claim 12 wherein said
fatty acid ester (V) comprises the reaction product of a fatty
acid, a dicarboxylic acid and a low molecular weight polyol having
3 or more hydroxyl groups, said fatty acid ester having an average
molecular weight of about 900 to 2500, a hydroxyl number of about
30 to 70 and an acid number of about 3 to 30.
18. The isocyanate-reactive component of claim 12 which
additionally comprises a reinforcing agent.
19. An isocyanate-reactive component which is suitable for the
production of an optionally cellular, polyurea elastomer molding
and comprises
(II) a polyether having at least two isocyanate-reactive groups and
a molecular weight of about 2000 to 8000 in which about 80% to 100%
of the isocyanate-reactive groups are primary and/or secondary
amino groups,
(III) about 5 to 50% by weight, based on the weight of
isomeric mixture of 1-methyl-3,5-diethyl-2,4-diaminobenzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene and
(IV) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of a zinc carboxylate containing 8 to 24 carbon
atoms per carboxylate group and
(V) about 2 to 15% by weight, based on the weight of
components (II) and (III), of an active hydrogen-containing fatty
acid ester having a molecular weight of about 800 to 3000 and
prepared by reacting an alcohol with an aliphatic, saturated or
unsaturated fatty acid, said ester being characterized in that at
least one aliphatic acid which contains more than 8 carbon atoms is
built into the molecule, said ester further characterized as having
an acid number of 0 to 40 and a hydroxyl number of 0 to 75, with at
least one of said numbers being greater than 0.
20. The isocyanate-reactive component of claim 19 wherein said
alcohol used to prepare said fatty acid ester (V) comprises a low
molecular weight polyol having 3 or more hydroxyl groups.
21. The isocyanate-reactive component of claim 19 wherein said
fatty acid ester (V) comprises the reaction product of a fatty
acid, a dicarboxylic acid and a low molecular weight polyol having
3 or more hydroxyl groups, said fatty acid ester having an average
molecular weight of about 900 to 2500, a hydroxyl number of about
30 to 70 and an acid number of about 3 to 30.
22. The isocyanate-reactive component of claim 19 which
additionally comprises a reinforcing agent.
23. A composition which comprises
(IV) a zinc carboxylate containing 8 to 24 carbon atoms per
carboxylate group and
(V) an active hydrogen-containing fatty acid ester having a
molecular weight of about 500 to 5000 and prepared by reacting an
alcohol with an aliphatic, saturated or unsaturated fatty acid,
said ester being characterized in that at least one aliphatic acid
which contains more than 8 carbon atoms is built into the molecule,
said ester further characterized as having an acid number of 0 to
100 and a hydroxyl number of 0 to 150 with at least one of said
numbers being greater than 0.
24. The composition of claim 23 which additionally comprises an
isomeric mixture of 1-methyl-3,5-diethyl-2,4-diamino-benzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene.
25. The composition of claim 23 wherein said fatty acid ester (V)
has an acid number of 0 to 40, a hydroxyl number of 0 to 75 and an
average molecular weight of about 800 to 3000.
26. The composition of claim 23 wherein said alcohol used to
prepare said fatty acid ester (V) comprises a low molecular weight
polyol having 3 or more hydroxyl groups.
27. The composition of claim 23 wherein said fatty acid ester (V)
comprises the reaction product of a fatty acid, a dicarboxylic acid
and a low molecular weight polyol having 3 or more hydroxyl groups,
said fatty acid ester having an average molecular weight of about
900 to 2500, a hydroxyl number of about to 70 and an acid number of
about 3 to 30.
28. An optionally cellular, polyurea elastomer molding which is
prepared by a process which comprises reacting a reaction mixture
containing
(I) a polyisocyanate,
(II) a polyether having at least two isocyanate-reactive groups and
a molecular weight of 1800 to 12,000 in which at least 50% of the
isocyanate-reactive groups are primary and/or secondary amino
groups,
(III) about 5 to 50% by weight, based on the weight of component
(II), of a chain extender comprising a sterically hindered aromatic
diamine and
(IV) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of a zinc carboxylate containing 8 to 24 carbon
atoms per carboxylate group and
(V) about 0.5 to 10% by weight, based on the weight of
components (II) and (III), of an active hydrogen-containing fatty
acid ester having a molecular weight of about 500 to 5000 and
prepared by reacting an alcohol with an aliphatic, saturated or
unsaturated fatty acid, said ester being characterized in that at
least one aliphatic acid which contains more than eight carbon
atoms is built into the molecule, said ester further characterized
as having an acid number of 0 to 100 and a hydroxyl number of 0 to
150 with at least one of said numbers being greater than 0,
wherein said zinc carboxylate and said fatty acid ester may each be
initially blended with either component (II), component (III) or a
mixture thereof and the reaction mixture is processed as a one-shot
system by the RIM process at an isocyanate index of about 70 to
130.
29. The elastomer molding of claim 28 wherein about 80 to 100% of
the isocyanate-reactive groups of component (II) are primary and/or
secondary amino groups.
30. The elastomer molding of claim 28 wherein said chain extender
comprises an isomeric mixture of
1-methyl-3,5-diethyl-2,4-diaminobenzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene.
31. The elastomer molding of claim 28 wherein said fatty acid ester
(V) has an acid number of 0 to 40, a hydroxyl number of 0 to 75 and
an average molecular weight of about 800 to 3000.
32. The elastomer molding of claim 28 wherein said alcohol used to
prepare said fatty acid ester (V) comprises a low molecular weight
polyol having 3 or more hydroxyl groups.
33. The elastomer molding of claim 28 wherein said fatty acid ester
(V) comprises the reaction product of a fatty acid, a dicarboxylic
acid and a low molecular weight polyol having 3 or more hydroxyl
groups, said fatty acid ester having an average molecular weight of
about 900 to 2500, a hydroxyl number of about 30 to 70 and an acid
number of about 3 to 30.
34. The elastomer molding of claim 28 wherein said reaction mixture
additionally contains a reinforcing agent.
35. An optionally cellular, polyurea elastomer molding which is
prepared by a process which comprises reacting a reaction mixture
containing
(I) a polyisocyanate which is liquid at room temperature,
(II) a polyether having at least two isocyanate-reactive groups and
a molecular weight of about 2000 to 8000 in which about 80% to 100%
of the isocyanate-reactive groups are primary and/or secondary
amino groups,
(III) about 5 to 50% by weight, based on the weight of component
(II) of a chain extender comprising an isomeric mixture of
1-methyl-3,5-diethyl-2,4-diaminobenzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene,
(IV) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of a zinc carboxylate containing 8 and 24 carbon
atoms per carboxylate group and
(V) about 2 to 15% by weight, based on the weight of components
(II) and (III) of an active hydrogen-containing fatty acid ester
having a molecular weight of about 800 to 3000 and prepared by
reacting an alcohol with an aliphatic, saturated or unsaturated
fatty acid, said ester being characterized in that at least one
aliphatic acid which contains more than 8 carbon atoms is built
into the molecule, said ester further characterized as having an
acid number of 0 to 40 and a hydroxyl number of 0 to 75, with at
least one of said numbers being greater than 0,
wherein said zinc carboxylate and said fatty acid ester may each be
initially blended with component (II), component (III) or a mixture
thereof and the reaction mixture is processed as a one-shot system
by the RIM process at an isocyanate index of about 70 to 130.
36. The elastomer molding of claim 35 wherein said alcohol used to
prepare said fatty acid ester (V) comprises a low molecular weight
polyol having 3 or more hydroxyl groups.
37. The elastomer molding of claim 35 wherein said fatty acid ester
(V) comprises the reaction product of a fatty acid, a dicarboxylic
acid and a low molecular weight polyol having 3 or more hydroxyl
groups, said fatty acid ester having an average molecular weight of
about 900 to 2500, a hydroxyl number of about 30 to 70 and an acid
number of about 3 to 30.
38. The elastomer molding of claim 35 wherein said reaction mixture
additionally contains a reinforcing agent.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a process for the preparation
of optionally cellular polyurea elastomer moldings which have
improved surface quality and to the polyurea elastomers prepared by
this process.
2. Description of the Prior Art
Reaction injection molding processes for the production of
optionally cellular polyurea elastomers have been described in U.S.
Pat. Nos. 4,433,067, 4,444,910 and 4,530,941. U.S. Pat. No.
4,774,263 is directed to the production of polyurea elastomers
using a mold release agent. This reference discloses that suitable
mold release agents are the salts of fatty acids having at least 12
carbon atoms and either primary mono-, di- or polyamines containing
2 or more carbon atoms or amines containing amide or ester groups
and having at least one primary, secondary or tertiary amino group
according to U.S. Pat. No. 3,726,952; blends of two or more of the
following in accordance with British Pat. No. 1,365,215: (1) esters
of monofunctional and/or polyfunctional carboxylic acids which
contain -COOH and/or -0H groups and have OH or acid numbers of at
least 5, (2) natural or synthetic oils, fats or waxes and (3) salts
according to U.S. Pat. No. 3,726,952; salts of saturated or
unsaturated aliphatic or cycloaliphatic carboxylic acids having at
least 8 carbon atoms and tertiary amines which do not contain amide
or ester groups in accordance with U.S. Pat. No. 4,098,731; and
reaction products of ricinoleic acid and long chain fatty acids in
accordance with U.S. Pat. No. 4,058,492. In addition, U.S. Pat.
Nos. 4,396,729 and 4,764,540 disclose polysiloxane-based internal
mold release agents for use in the production of polyurea
elastomers.
Finally, U.S. Pat. Nos. 4,519,965 and 4,581,386 are directed to the
use of internal mold release agent mixtures for either polyurethane
and/or polyurea elastomers which are based on a zinc carboxylate
and a solubilizer to maintain the zinc carboxylate in solution in
the isocyanate-reactive component used to prepare the elastomer.
One of the problems associated with the use of zinc carboxylates as
mold release agents for the production of polyurea elastomers is
that the surfaces of the resulting elastomers are unacceptably
porous and rough.
An object of the present invention is to overcome these
difficulties and improve the surface quality of polyurea elastomers
prepared using zinc carboxylates as the mold release agent. This
object can be achieved in accordance with the present invention as
described hereinafter.
SUMMARY OF THE INVENTION
The present invention is directed to a process for the production
of optionally cellular, polyurea elastomer moldings by reacting a
mixture containing
(I) a polyisocyanate,
(II) a polyether having at least two isocyanate-reactive groups and
a molecular weight of 1800 to 12,000 in which at least 50% of the
isocyanate-reactive groups are primary and/or secondary amino
groups,
(III) about 5 to 50% by weight, based on the weight of component
(II), of a chain extender comprising a sterically hindered aromatic
diamine,
(IV) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of a zinc carboxylate containing 8 to 24 carbon
atoms per carboxylate group and
(V) about 0.5 to 10% by weight, based on the weight of components
(II) and (III), of an active hydrogen-containing fatty acid ester
having a molecular weight of about 500 to 5000 and prepared by
reacting an alcohol with an aliphatic, saturated or unsaturated
fatty acid, said ester being characterized in that at least one
aliphatic acid which contains more than eight carbon atoms is built
into the molecule, said ester further characterized as having an
acid number of 0 to 100 and a hydroxyl number of 0 to 150 with at
least one of said numbers being greater than 0,
wherein the zinc carboxylate and the fatty acid ester may each be
initially blended with either component (II), component (III) or a
mixture thereof and the reaction mixture is processed as a one-shot
system by the RIM process at an isocyanate index of about 70 to
130.
The present invention is also directed to an isocyanate-reactive
component for use in a RIM process based on components (II), (III),
(IV) and (V) and to an internal mold release agent mixture based on
components (IV) and (V) and, optionally, (III). Finally, the
present invention is directed to the optionally cellular polyurea
elastomers prepared by the above process.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term "polyurea" refers not only to pure
polyureas, i.e., polyisocyanate polyaddition products prepared
exclusively from polyisocyanates and polyamines, but also to
polyisocyanate polyaddition products prepared from polyamines and
other compounds containing isocyanate-reactive groups such as
polyhydroxyl compounds, provided that at least 50% of the
isocyanate-reactive groups are primary and/or secondary amino
groups.
The polyisocyanate component (I) to be used in accordance with the
present invention may be an aliphatic, cycloaliphatic, araliphatic
or preferably an aromatic polyisocyanate, i.e., a polyisocyanate in
which all of the isocyanate groups are aromatically bound. Examples
of aromatic polyisocyanates include 2,4- and/or
2,6-diisocyanatotoluene; 2,2'-, 2,4'- and/or
4,4'-diisocyanatodiphenylmethane, mixtures of the last-mentioned
isomers with their higher homologs (such as those obtained by
phosgenating aniline/formaldehyde condensates); compounds
containing urethane groups obtained as products of reaction of the
above-mentioned di- and/or polyisocyanates with subequivalent
quantities of aliphatic polyhydroxyl compounds having molecular
weights of 62 to 700, (e.g. ethylene glycol, trimethylol propane,
propylene glycol, dipropylene glycol or polypropylene glycols
within the above-mentioned molecular weight range); di- and/or
polyisocyanates modified by the partial carbodiimidization of the
isocyanate groups of the above-mentioned di- and/or
polyisocyanates; methyl-substituted diisocyanates of the diphenyl
methane series or mixtures thereof (for example, those described in
European Published Application No. 0,024,665); or any mixtures of
such aromatic di- and polyisocyanates.
Included among the preferred isocyanate starting materials are the
derivatives of 4,4'-diisocyanatodiphenylmethane which are liquid at
room temperature. Specific examples of such compounds are
polyisocyanates containing urethane groups obtainable according to
German Patent No. 1,618,380 (U.S. Pat. No. 3,644,457) by reacting
one mole of 4,4'-diisocyanatodiphenylmethane with about 0.05 to 0.3
moles of low molecular weight diols or triols, preferably
polypropylene glycols having a molecular weight below 700; and
diisocyanates based on 4,4'-diisocyanatodiphenylmethane containing
carbodiimide and/or uretone imine groups such as those disclosed in
U.S. Pat. Nos. 3,152,162, 3,384,653, 3,449,256, and 4,154,752, and
German Offenlegungsschrift No. 2,537,685. Also included among the
preferred polyisocyanates are the corresponding modification
products based on mixtures of 2,4'- and
4,4'-diisocyanatodiphenylmethane or mixtures of the above-described
modified 4,4'-diisocyanatodiphenylmethanes with minor quantities of
higher than difunctional polyisocyanates of the diphenylmethane
series. Such polyisocyanates are described in German
Offenlegungsschrift No. 2,624,526. The preferred polyisocyanates
are generally polyisocyanates or polyisocyanate mixtures of the
diphenylmethane series which are liquid at room temperature and
have optionally been chemically modified as described above, have
an average isocyanate functionality of 2 to 2.2 (preferably 2) and
contain 4,4'-diisocyanatodiphenylmethane as the main component
(preferably in an amount of more than 50% by weight).
Another group of preferred polyisocyanates are semiprepolymers
based on the above-mentioned monomeric polyisocyanates with
subequivalent quantities of non-fatty, hydroxy polyesters. It has
been disclosed in copending application, Attorney's Docket No.
Mo-3175, that the use of these polyester-based semi-prepolymers (in
place of the urethane group-containing polyisocyanates generally
used for the preparation of RIM elastomers) results in polyurea
elastomers which are not brittle at demold, even when processed at
conventional mold temperatures. The semi-prepolymers have an
isocyanate content of about 10 to 30% by weight, preferably about
15 to 25%. The polyisocyanate component generally contains at least
20% by weight, preferably at least 30% by weight and more
preferably at least 40% by weight of these polyester-based
prepolymers in order to obtain molded elastomers which are not
brittle.
The hydroxy polyesters generally have a hydroxyl functionality of 1
to 4, preferably 2 to 3 and more preferably 2, and a molecular
weight of about 500 to 4000, preferably about 500 to 2500. The
hydroxy polyesters are based on the reaction products of
polyhydric, preferably dihydric alcohols to which trihydric
alcohols may be added, and mono- or polybasic, preferably dibasic
carboxylic acids. Instead of free mono- or polycarboxylic acids,
the corresponding mono- or polycarboxylic acid anhydrides or mono-
or polycarboxylic acid esters of lower alcohols or mixtures thereof
may be used for preparing the polyesters. The mono- or
polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic
and/or heterocyclic and may be unsaturated and/or substituted, e.g.
by halogen atoms. The aliphatic monocarboxylic acids are preferably
non-fatty carboxylic acids containing less than 12, preferably 8 or
less carbon atoms. Saturated, aliphatic dicarboxylic acids are
preferred. Examples of suitable acids include succinic acid, adipic
acid, suberic acid, azelaic acid, sebacic acid, phthalic acid,
isophthalic acid, trimellitic acid, phthalic acid anhydride,
tetrahydrophthalic acid anhydride, hexahydrophthalic acid
anhydride, tetrachlorophthalic acid anhydride, endomethylene
tetrahydrophthalic acid anhydride, glutaric acid anhydride, maleic
acid, maleic acid anhydride, fumaric acid, dimethyl terephthalate
and bis-glycol terephthalate. Suitable polyhydric alcohols include
ethylene glycol, propylene glycol-(1,2) and -(1,3), butylene
glycol-(1,4) and -(2,3), hexane diol-(1,6), octane diol-(1,8),
neopentyl glycol, cyclohexane dimethanol
(1,4-bis-hydroxymethyl-cyclohexane), 2-methyl-1,3-propane diol,
glycerol, trimethylol propane, hexane triol-(1,2,6), butane
triol-(1,2,4), trimethylol ethane, triethylene glycol,
tetraethylene glycol, polyethylene glycols, dipropylene glycol,
polypropylene glycol, dibutylene glycol and polybutylene glycols.
The polyesters may also contain a proportion of carboxyl end
groups. Polyesters of lactones, e.g. .epsilon.-caprolactam, or
hydroxy carboxylic acids, e.g. .omega.-hydroxy caproic acid, may
also be used. The semi-prepolymers are prepared in known manner by
adding a sufficient amount of the hydroxy polyester to the
polyisocyanate to achieve the desired NCO content. It is also
possible to mix the hydroxy polyester with a portion of the
polyisocyanate to form an isocyanate-terminated prepolymer which is
subsequently mixed with additional quantities of the polyisocyanate
or a different polyisocyanate.
The polyethers (component II) to be used in accordance with the
present invention contain at least two isocyanate-reactive groups
in end positions and have an average molecular weight (calculated
from the functionality and the isocyanate-reactive group content)
of about 1800 to 12,000, preferably about 2000 to 8000. At least
about 50 equivalent %, preferably about 80 to 100 equivalent % of
the isocyanate-reactive end groups are primary and/or secondary
(preferably primary) aromatically or aliphatically bound amino
groups with the remainder being primary and/or secondary
aliphatically bound hydroxyl groups. When polyether mixtures are
used, individual components of the mixture may have a molecular
weight below 1800 (for example between 500 and 1800), provided that
the average molecular weight of the mixtures is within the range of
1800 to 12,000. The use of mixtures containing large quantities of
individual components which have molecular weights below 1800 is,
however, not preferred, even when the average molecular weight is
within the disclosed ranges.
Compounds containing amino end groups may be prepared by the
conversion of existing end groups or they may be attached to the
polyether chain by urethane, ether or ester groups. Suitable
polyether polyols for preparing the amine-terminated polyethers are
known and disclosed in U.S. Pat. Nos. 4,305,857 and 4,218,543, both
of which are herein incorporated by reference.
The "amino polyethers" may be prepared by known methods. One such
method is the amination of polyhydroxy polyethers (e.g.,
polypropylene glycol ethers) by reaction with ammonia in the
presence of Raney nickel and hydrogen (Belgium Patent No. 634,741).
U.S. Pat. No. 3,654,370 discloses the preparation of
polyoxyalkylene polyamines by reaction of the corresponding polyol
with ammonia and hydrogen in the presence of a nickel, copper or
chromium catalyst. The preparation of polyethers containing amino
end groups by the hydrogenation of cyanoethylated polyoxypropylene
ethers is described in German Patent No. 1,193,671. Other methods
for the preparation of polyoxyalkylene (polyether) amines are
described in U.S. Pat. Nos. 3,155,728 and 3,236,895 and French
Patent No. 1,551,605. French Patent No. 1,466,708 discloses the
preparation of polyethers containing secondary amino end
groups.
Relatively high molecular weight polyhydroxy polyethers suitable
for the process of the present invention may be converted into the
corresponding anthranilic acid esters by reaction with isatoic acid
anhydride. German Offenlegungsschriften No. 2,019,432 and 2,619,840
and U.S. Pat. Nos. 3,808,250; 3,975,428; and 4,016,143 disclose
methods for making polyethers containing aromatic end groups.
Relatively high molecular weight compounds containing amino end
groups may be obtained according to German Offenlegungsschrift No.
2,546,536 or U.S. Pat. No. 3,865,791 by reacting isocyanate
prepolymers based on polyhydroxy polyethers with
hydroxyl-containing enamines, aldimines or ketimines and
hydrolyzing the reaction product.
Amino polyethers which have been obtained by the hydrolysis of
compounds containing isocyanate end groups (U.S. Pat. No.
4,774,263, herein incorporated by reference in its entirety) are
preferred starting materials and can be used alone or in admixture
with other amino polyethers, especially those obtained by the
amination of polyether polyols. To prepare these hydrolyzed amino
polyethers, polyethers preferably containing two or three hydroxyl
groups are reacted with excess quantities of polyisocyanates to
form isocyanate-terminated prepolymers and the isocyanate groups
are then converted in a second step into amino groups by
hydrolysis. Other patents relating to the preparation of these
amino polyethers include U.S. Pat. Nos. 4,532,317; 4,506,039;
4,540,270; 4,565,645; 4,525,534; 4,515,923; 4,525,590; 4,501,873;
4,578,500; 4,386,218; 4,472,568; 4,532,266; and 4,456,730.
Additional methods are disclosed in European Patent Application
Nos. 217,247; 178,525; 97,299; 75,770; 219,035; and 218,053.
Also preferred are polyethers containing amino phenoxy end groups
and having a low viscosity. These aminopolyethers may be
economically prepared in accordance with German Offenlegungsschrift
No. 3,713,858, and may be used alone or in admixture with the other
previously described aminopolyethers.
The "amino polyethers" used in accordance with the present
invention are in many cases mixtures of the compounds described
above. These mixtures generally should contain (on a statistical
average) two to three isocyanate-reactive end groups. In the
process of the present invention, the "amino polyethers" may also
be used as mixtures with polyhydroxy polyethers which are free from
amino groups (such as those previously disclosed as precursors for
the amino polyethers, or highly branched polyether polyols having
an average hydroxyl functionality of about 3 to 6 and molecular
weights of about 500 to 1000), although such mixtures are less
preferred. If such mixtures are used, however, it is necessary to
ensure that at least about 50 equivalent % of the isocyanate
reactive groups present in the mixture are primary and/or secondary
amino groups. It is also possible to use mixed amino/hydroxyl
polyethers, i.e., polyethers containing both amino and hydroxyl
groups, provided that at least 50% of the isocyanate-reactive
groups in the polyether component are primary and/or secondary
amino groups. These mixed amino/hydroxyl polyethers may be
prepared, e.g., by aminating only a portion of the hydroxyl groups
of a polyether polyol.
Suitable chain extenders (component III) include the known low
molecular isocyanate-reactive compounds such as aromatic
polyamines, especially diamines, having molecular weights of less
than about 800, preferably less than about 500.
Preferred chain extenders include the sterically hindered aromatic
diamines which contain at least one linear or branched alkyl
substituent in the ortho position to the first amino group and at
least one, preferably two, linear or branched alkyl substituents
containing at least one, preferably one to three carbon atoms in
the ortho position to the second amino group. These aromatic
diamines include 1-methyl-3,5-diethyl-2,4-diaminobenzene,
1-methyl-3,5-diethyl-2,6-diaminobenzene,
1,3,5-trimethyl-2,4-diaminobenzene,
1-methyl-5-t-butyl-2,4-diaminobenzene,
1-methyl-5-t-butyl-2,6-diaminobenzene,
1,3,5-triethyl-2,4-diaminobenzene,
3,5,3',5'-tetraethyl-4,4'-diaminodiphenylmethane,
3,5,3',5'-tetraisopropyl-4,4'-diaminodiphenylmethane,
3,5-diethyl-3',5'-diisopropyl-4,4'-diaminodiphenylmethane,
3,3'-diethyl-5,5'-diisopropyl-4,4'-diaminodiphenylmethane,
1-methyl-2,6-diamino-3-isopropylbenzene and mixtures of the above
diamines. Most preferred are mixtures of
1-methyl-3,5-diethyl-2,4-diaminobenzene and
1-methyl-3,5-diethyl-2,6-diaminobenzene in a weight ratio between
about 50:50 to 85:15, preferably about 65:35 to 80:20.
In addition, unhindered aromatic polyamines may be used in
admixture with the sterically hindered chain extenders and include
2,4- and/or 2,6-diaminotoluene, 2,4'- and/or
4,4'-diaminodiphenylmethane, 1,2- and 1,4-phenylene diamine,
naphthalene-1,5-diamine and triphenyl methane-4,4',4"-triamine. The
difunctional and polyfunctional aromatic amine compounds may also
exclusively or partly contain secondary amino groups such as
4,4'-di-(methylamino)-diphenylmethane or
1-methyl-2-methylamino-4-aminobenzene. Liquid mixtures of
polyphenyl polymethylene polyamines of the type obtained by
condensing aniline with formaldehyde are also suitable. Generally
the nonsterically hindered aromatic diamines and polyamines are too
reactive to provide sufficient processing time in a RIM system.
Accordingly, these diamines and polyamines should be used in
combination with one or more of the previously mentioned sterically
hindered diamines.
The chain extender (III) is used in quantities of about 5 to 50%,
preferably about 8 to 30% and most preferably about 12 to 26% by
weight, based on the weight of the high molecular weight
isocyanate-reactive component (II).
In addition to components I, II and III, the compositions according
to the present invention also contain metallic carboxylates (IV),
preferably zinc carboxylates, as internal mold release agents.
Suitable metallic carboxylates which may be used in accordance with
the present invention are based on C.sub.8 -C.sub.24, branched or
straight chain fatty acids which may be saturated or unsaturated,
preferably saturated. The carboxylates also include the commercial
preparations of a specific carboxylate which also contains
impurities or by-products of other fatty acid derivatives. For
example, commercial "stearates" may also contain significant
quantities of palmitates, myristates, etc. and commercial "tall
oil" derivatives normally contain mixtures of stearates,
palmitates, oleates, etc. Examples of preferred zinc carboxylates
include zinc stearate, zinc oleate, zinc octoate, zinc laurate,
zinc behenate and zinc ricinoleate; zinc stearate is especially
preferred. In view of the large quantities of amine-terminated
polyethers used in accordance with the present invention, it is not
necessary to add low molecular weight compatibilizers as disclosed
in U.S. Pat. No. 4,519,965; however, these compatibilizers
(disclosed at columns 4 and 5 of U.S. Pat. No. 4,519,965, herein
incorporated by reference) may be included in the compositions
according to the present invention. The metallic carboxylates are
generally used in amounts of about 0.5 to 10% by weight, preferably
about 1 to 6% by weight and more preferably about 1 to 4% by
weight, based on the weight of components (II) and (III). The
metallic carboxylates may be incorporated into component (II),
component (III) or mixtures thereof.
In accordance with the present invention active hydrogen-containing
fatty acid esters are incorporated into component (II), component
(III) or mixtures thereof in order to improve the surface quality
of the polyurea elastomers. The fatty acid esters may first be
blended with the metallic carboxylates (IV) to form an internal
mold release agent mixture prior to incorporating this mixture into
components (II) and/or (III). However, the metallic carboxylates
and fatty acid esters may also be added separately or one may be
added to component (II) and one may be added to component
(III).
Suitable fatty acid esters to be incorporated in accordance with
the present invention are those in which at least one aliphatic
acid which contains more than eight carbon atoms is built into the
molecule and which have acid numbers of 0 to 100, preferably 0 to
40 and hydroxyl numbers of 0 to 150, preferably 0 to 75, wherein at
least one of these two values is greater than 0. The fatty acid
esters are generally present in an amount of about 0.5 to 10% by
weight, preferably about 1 to 6% by weight and more preferably
about 1 to 4% by weight, based on the weight of components (II) and
(III), in order to improve the surface quality of the polyurea
elastomers.
The fatty acid esters used may also have the character of
polyesters or mixed esters and may be prepared both from
monofunctional and polyfunctional carboxylic acids and/or alcohols.
The fatty acid esters may be prepared from several different types
of fatty acids or carboxylic acids and/or alcohols so that fatty
acid esters with an average molecular weight of about 500 to about
5000, preferably about 800 to 3000, are obtained by the process of
mixed condensation.
Amines (blended with alcohols) or amino alcohols (optionally
blended with alcohols) may also be used in the preparation of fatty
acid esters and result in fatty acid mixed esters which contain
basic or amide groups. These mixed esters are suitable for the
process according to the invention. Such mixed esters can be
obtained by using ammonia, monoalkyl amines or dialkylamines or
their alkoxylation products (for example with ethylene oxide,
propylene oxide or higher epoxides), or by using acid amides which
contain carboxyl groups or alcohol groups. These acid amides may
also be obtained by the amidation of carboxylic acids with
monoalkanolamines or dialkanolamines such as ethanolamine,
diethanolamine, propanolamine, dipropanolamine or the like. The
fatty acid esters used for the reaction with the polyisocyanates
are preferably those which can be prepared by esterifying
carboxylic acids with alcohols or which can be obtained from
natural substances. Suitable examples of alcohols include those set
forth for the preparation of the polyester precursors of the
polyisocyanate component and also butanol, hexanol, octanol
isomers, dodecanol, oleyl alcohol, other fatty alcohols, natural or
synthetic steroid alcohols, ricinoleic acid, pentaerythritol,
sorbitol, hexitol, various sugars or addition products of alkylene
oxides (such as ethylene oxide or propylene oxide) with these
alcohols, and the like. Glycerol, trimethylol propane,
pentaerythritol and sorbitol are particularly suitable.
The carboxylic acids used may be saturated or unsaturated,
preferably aliphatic, and include octane carboxylic acids, dodecane
acids, natural fatty acids such as ricinoleic acid, oleic acid,
alaidic acid, stearic acid, palmitic acid, linoleic acid, linolenic
acid, train oil fatty acids, fatty acids obtained from coconut oil,
tallow fatty acids or fatty acids obtained by paraffin oxidation,
tall oil fatty acids, succinic acid, maleic acid, citric acid,
azelaic acid, adipic acid or higher dicarboxylic and polycarboxylic
acids, oligomerization products of unsaturated carboxylic acids and
addition products of maleic acid with natural and synthetic oils,
and the like. The following are particularly suitable: oleic acid,
linoleic acid, ricinoleic acid and adipic acid.
Preparation of the fatty acid esters is most suitably carried out
by the co-condensation of the alcohols and acids at temperature
above 100.degree. C., preferably at about 120.degree. to
180.degree. C., optionally in a vacuum, the process of the
elimination of water being continued until the desired hydroxyl and
acid numbers or average molecular weights have been obtained. The
process of esterification may, of course, be catalyzed with acid or
basic catalysts and the water may be eliminated by azeotropic
distillation. The products prepared and used according to the
invention preferably contain hydroxyl and/or carboxylic acid
groups.
Fatty acid esters which have been found to be particularly suitable
for the process are the cocondensates of oleic acid with a
dicarboxylic acid (such as adipic acid) and a polyfunctional
alcohol (such as pentaerythritol), which have molecular weights of
about 900 to 2500, hydroxyl numbers of about 30 to 70 and acid
numbers of about 3 to 30.
There is not always a direct stoichiometric connection between the
acid numbers and the hydroxyl numbers obtained and the molar ratios
of the components used, possibly because side reactions of unknown
type take place with the esterification.
Castor oil and ricinoleic acid polyesters which have a molecular
weight of between 800 and 2500 are also of particular interest.
Auxiliary agents and additives including additional internal mold
release agents, reinforcing agents, blowing agents, catalysts,
surface active additives (emulsifiers and foam stabilizers),
reaction retarders, cell regulators, fillers, pigments, flame
retardant agents, age resistors, stabilizers to protect against
weathering, plasticizers, fungistatic and bacteriostatic
substances, may also be included in the compositions according to
the present invention. Examples of these types of auxiliary agents
and additives are set forth in U.S. Pat. Nos. 4,254,228 and
4,581,386, both of which are herein incorporated by reference in
their entireties. In addition, these additives have been described
in Kunststoff-Handbuch, Vol. VI, published by Vieweg and Hochtlen,
Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 103 to 113.
The compositions according to the present invention may be molded
using conventional RIM processing techniques. In general, two
separate streams are intimately mixed and subsequently injected
into a suitable mold, although it is possible to use more than two
streams. The first stream contains the polyisocyanate component
(I), while the second stream contains the high molecular weight
isocyanate-reactive component (II), the chain extender (III), the
chain extender (IV), the fatty acid ester (V) and generally any
other additive which is to be included.
Prior to use, a mixture is prepared from components (II), (III),
(IV) and (V) to form a second stream and agitated briefly to ensure
homogeneity. If used, a reinforcing agent may be added to the
mixture at this time.
The invention is further illustrated, but is not intended to be
limited by the following examples in which all parts and
percentages are by weight unless otherwise specified.
EXAMPLES
Description of Materials
Polyol A: A TMP/water-initiated (4.5:1 wt. ratio) hydroxy
polyoxypropylene having an OH number of 56 and a functionality of
2.4.
Polyol B: A glycerine-initiated poly(oxyalkylene)-polyether triol
having an OH number of 35 and prepared from 4.6% propylene oxide
followed by 4.7% ethylene oxide, followed by 82.3% propylene oxide
and, finally 8.4% ethylene oxide.
Polyol C: A mixture of two parts of Polyol A with one part of
Polyol B.
Polyol D: A polyester polyol having a molecular weight of 2000 and
based on adipic acid and a mixture of ethylene glycol and butylene
glycol in a 1:1 molar ratio.
Polyol E: A glycerine-initiated poly(oxyalkylene)-polyether triol
having an OH number of 28 and prepared from 83 wt. % propylene
oxide followed by 17 % ethylene oxide.
Amine-Terminated Polyether A: 1 mole of Polyol C was reacted with
2.6 moles of 2,4-toluylene diisocyanate to form an
isocyanate-terminated prepolymer and the terminal isocyanate groups
were subsequently converted to primary amino groups.
Amine-Terminated Polyether B: A blend of aliphatically-bound
amine-terminated polyoxypropylenes having an average equivalent
weight of about 1,000, an average functionality of about 2.5 and
supplied by Texaco Chemical Company as Jeffamine LMT-3001.
Amine-Terminated Polyether C: 1 mole of Polyol E was reacted with 3
moles of 2,4-toluylene diisocyanate to form an
isocyanate-terminated prepolymer and the terminal isocyanate groups
were subsequently converted to primary amino groups.
Chain Extender A: A commercial preparation of diethyl toluene
diamine (DETDA) which is an isomeric mixture of
1-methyl-3,5-diethyl-2,4-diamino-benzene and
1-methyl-3,5-diethyl-2,6-diamino-benzene in a ratio between 65:35
and 80:20.
Cross-Linker A: An amine-initiated poly(oxyalkylene)polyether
tetrol having a hydroxyl number of about 630 and obtained by the
addition of about 5 moles of propylene oxide to one mole of
ethylene diamine.
Fatty Acid Ester A: Castor oil supplied as DB Oil by CasChem.
Fatty Acid Ester B: A polyester having an OH number of 50 and an
acid number of 5 which was prepared from 2.5 moles of
pentaerythritol, 6 moles of oleic acid and 1 mole of adipic
acid.
Surfactant A: A commercial silicone surfactant supplied as L 5430
by Union Carbide.
Surfactant B: A commercial silicone surfactant supplied as L-5304
by Union Carbide.
Additive A: A functional silane modifier identified as
gamma-glycidoxypropyltrimethoxysilane and supplied by Dow Corning
Corporation as Z-6040 or equivalent.
Additive B: Bis-(3-dimethylaminopropyl)-amine.
Additive C: Dimethylformamide (DMF).
Polyisocyanate A: A mixture having an overall isocyanate content of
19% and based on 94% by weight of an isocyanate-terminated
prepolymer prepared from 4,4'-diphenyl-methane diisocyanate and
Polyol D and 6% by weight of carbodiimidized 4,4'-diphenylmethane
diisocyanate having an isocyanate equivalent weight of 143.
Polyisocyanate B: An aniline/formaldehyde condensation product
containing 41% of 4,4'-diphenylmethane diisocyanate, 18% of the
2,4'-isomer, 2% of the 2,2'-isomer and the remainder higher
functional homologs.
Polyisocyanate C: A mixture of 80 parts of Polyisocyanate A and 20
parts of Polyisocyanate B.
Polyisocyanate D: A liquid semi-prepolymer prepared by reacting
4,4'-diphenylmethane diisocyanate and tripropylene glycol in a
molar ratio of about 5:1 to provide a product having an NCO content
of about 23% and a viscosity at 25.degree. C. of 725.+-.175
cps.
Polyisocyanate E: An aniline/formaldehyde condensation product
containing 44.4% of 4,4'-diphenylmethane diisocyanate, 19% of the
2,4'-isomer, 2.6% of the 2,2'-isomer and the remainder higher
functional homologs.
Polyisocyanate F: A blend of 80 parts of Polyisocyanate A and 20
parts of Polyisocyanate E.
Polyisocyanate G: An aniline/formaldehyde condensation product
containing 54.4% of 4,4'-diphenylmethane diisocyanate, 2.6% of the
2,4'-isomer and the remainder higher functional homologs.
Polyisocyanate H: A mixture of equal parts of Polyisocyanate A and
carbodiimidized 4,4'-diphenylmethane diisocyanate having an
isocyanate equivalent weight of 143.
Polyisocyanate I: An isocyanate-terminated prepolymer having an NCO
content of 19.2% and based on 38% of Polyol D, 12.4% of
Polyisocyanate G and 49.6% of 4,4'-diisocyanatodiphenylmethane.
Polyisocyanate J: A blend of 80 parts of Polyisocyanate A and 20
parts of Polyisocyanate G.
EXAMPLES 1-17:
The resin blends and polyisocyanates set forth in the following
table were reacted at an isocyanate index of 105 to form polyurea
elastomers. The elastomers were prepared in a Cincinnati Milacron
RIM-90 using a plaque tool (P) or in a Cincinnati Milacron RIM-125
using a General Motors door panel (D). The reaction mixtures
generally possessed good flowability and the elastomers possessed
good green strength and were stiff at demold. After cooling, the
elastomers were evaluated for surface quality. Prior to conducting
the examples, the surface of the mold was treated with an external
soap release agent, ChemTrend RCTW 2006.
______________________________________ Mixhead Type Adjustable
Injection Rate, pounds per second 5.1 Part Weight, pound 5.7 Mold
Temperature, .degree.F. 150 Resin Blend, specific gravity, g/cc
1.256 Material Temperature, .degree.F. Polyisocyanate Component 30
Resin Component 120-130 Mix Pressures, psi Polyisocyanate Component
1900-2000 Resin Blend Component 2000-2100 Demold Time, seconds 35
______________________________________
__________________________________________________________________________
EXAMPLE NO. 1 2 Comp Comp 3 4 5 6 7 8 9
__________________________________________________________________________
Amine-Terminated 65 68 63 63 63 65.9 63 65 65 Polyether A Chain
Extender A 28 25 28 28 26 25.1 28 26 26 Cross-Linker A 3 3 3 3 3 3
3 3 3 Zinc Stearate 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Surfactant
A,1.0 A,1.0 B,0.5 B,075 B,0.75 B,0.75 B,0.75 B,0.75 B,0.75 Additive
A 0.5 0.5 1.0 0.75 0.75 0.75 0.75 0.75 0.75 Fatty Acid Ester A --
-- 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Flakeglass.sup.1, % 20 25 20 20 20
20 20 20 20 Polyisocyanate A A A A A H I J C Mold P P P D D P P P P
__________________________________________________________________________
EXAMPLE NO. 10.sup.2 12 Comp 11.sup.3 Comp 13 14 15 16
__________________________________________________________________________
Amine-Terminated A,66.5 A,62 A,67 B,65 B,65 C,68.25 C,68.25
Polyether Chain Extender A 28 28 26 26 26 26 26 Cross-Linker A 1 3
3 3 3 3 3 Zinc Stearate 2.0 2.5 2.5 2.5 2.5 2 2 Surfactant B 0.75
0.75 0.75 0.75 0.75 0.75 0.75 Additive A 0.75 0.75 0.75 0.75 0.75
-- -- Fatty Acid Ester B -- 2 -- 2 2 -- 2 Flakeglass, % 20 20 20 20
20 17.sup.4 17.sup.4 Polyisocyanate C C C D C F F Mold P P P P P P
P
__________________________________________________________________________
.sup.1 % flakeglass is based on total reaction mixture including
polyisocyanate .sup.2 also contained 1.0 part of Additive B .sup.3
also contained 1.0 part of Additive C .sup.4 surface treated mica
from Huber
In the preceding examples the surface quality of the elastomers
which were prepared in accordance with the present invention was
much better than the surface quality of the elastomers prepared in
the comparison examples, which were porous and rough. Particular
attention is directed to Examples 15-16. In Example 15 seven
elastomers were prepared from a resin blend which did not contain a
fatty acid ester and resulted in elastomers which contained sink
marks and light mix worms. Example 16 continued Example 15;
however, the next 7 elastomers were prepared from a resin blend
which contained the indicated amount of fatty acid ester. The
surface of these elastomers did not contain sink marks or mix
worms.
Although the invention has been described in detail in the
foregoing for the purpose of illustration, it is to be understood
that such detail is solely for that purpose and that variations can
be made therein by those skilled in the art without departing from
the spirit and scope of the invention except as it may be limited
by the claims.
* * * * *